People in their 40s and 50s with no children, how does it feel?

I'm not good around kids, so I made a decision to be without children pretty early on. So, to answer your question, I guess it feels... normal? It's hard to describe in more detail, because I don't have a reference to compare it to.

That said, I've seen what kind of struggles - emotional, financial or otherwise - my kid-having friends and family have been going through and I would be a liar if I said I never thought "I'm glad I don't have to go through this shit" more than on one occasion.